// Copyright (C) 2021-present sam (starshines.gay)
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published
// by the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

using System.ComponentModel;
using Catalogger.Backend.Cache;
using Catalogger.Backend.Cache.InMemoryCache;
using Catalogger.Backend.Database.Repositories;
using Catalogger.Backend.Extensions;
using Remora.Commands.Attributes;
using Remora.Commands.Groups;
using Remora.Discord.API;
using Remora.Discord.API.Abstractions.Objects;
using Remora.Discord.Commands.Feedback.Services;
using Remora.Discord.Commands.Services;
using Remora.Discord.Pagination.Extensions;
using Remora.Rest.Core;
using IResult = Remora.Results.IResult;

namespace Catalogger.Backend.Bot.Commands;

[Group("ignored-users")]
[Description("Manage users ignored for logging.")]
public class IgnoreUserCommands(
    GuildRepository guildRepository,
    GuildCache guildCache,
    IMemberCache memberCache,
    UserCache userCache,
    ContextInjectionService contextInjection,
    FeedbackService feedbackService
) : CommandGroup
{
    [Command("add")]
    [Description("Add a user to the list of ignored users.")]
    public async Task<IResult> AddIgnoredUserAsync([Description("The user to ignore")] IUser user)
    {
        var (_, guildId) = contextInjection.GetUserAndGuild();
        var guildConfig = await guildRepository.GetAsync(guildId);

        if (guildConfig.Channels.IgnoredUsers.Contains(user.ID.Value))
            return await feedbackService.ReplyAsync(
                "That user is already being ignored.",
                isEphemeral: true
            );

        guildConfig.Channels.IgnoredUsers.Add(user.ID.Value);
        await guildRepository.UpdateChannelConfigAsync(guildId, guildConfig.Channels);

        return await feedbackService.ReplyAsync(
            $"Successfully added {user.PrettyFormat()} to the list of ignored users."
        );
    }

    [Command("remove")]
    [Description("Remove a user from the list of ignored users.")]
    public async Task<IResult> RemoveIgnoredUserAsync(
        [Description("The user to stop ignoring")] IUser user
    )
    {
        var (_, guildId) = contextInjection.GetUserAndGuild();
        var guildConfig = await guildRepository.GetAsync(guildId);

        if (!guildConfig.Channels.IgnoredUsers.Contains(user.ID.Value))
            return await feedbackService.ReplyAsync(
                "That user is already not ignored.",
                isEphemeral: true
            );

        guildConfig.Channels.IgnoredUsers.Remove(user.ID.Value);
        await guildRepository.UpdateChannelConfigAsync(guildId, guildConfig.Channels);

        return await feedbackService.ReplyAsync(
            $"Successfully removed {user.PrettyFormat()} from the list of ignored users."
        );
    }

    [Command("list")]
    [Description("List currently ignored users.")]
    public async Task<IResult> ListIgnoredUsersAsync()
    {
        var (userId, guildId) = contextInjection.GetUserAndGuild();
        if (!guildCache.TryGet(guildId, out var guild))
            throw new CataloggerError("Guild was not cached");

        var guildConfig = await guildRepository.GetAsync(guildId);

        if (guildConfig.Channels.IgnoredUsers.Count == 0)
            return await feedbackService.ReplyAsync("No users are being ignored right now.");

        var users = new List<string>();
        foreach (var id in guildConfig.Channels.IgnoredUsers)
        {
            var user = await TryGetUserAsync(guildId, DiscordSnowflake.New(id));
            users.Add(user?.PrettyFormat() ?? $"*(unknown user {id})* <@{id}>");
        }

        return await feedbackService.SendContextualPaginatedMessageAsync(
            userId,
            DiscordUtils.PaginateStrings(users, $"Ignored users for {guild.Name} ({users.Count})")
        );
    }

    private async Task<IUser?> TryGetUserAsync(Snowflake guildId, Snowflake userId) =>
        (await memberCache.TryGetAsync(guildId, userId))?.User.Value
        ?? await userCache.GetUserAsync(userId);
}